Information on GM Vortec 8.1 turbo engine

[msantiago]

I am looking for an engine integrator that can supply GM 8.1 engine with turbo. Also I would appreciate any data on the mechanical efficency of this engine.

 

[ivymike]

What do you mean when you say the mechanical efficiency of the engine? BSFC?

 

[msantiago]

Hello Ivymike

This is correct, I am looking for BSFC. I have not been able find a value for this parameter on the engine Datasheet from GM.

 

[GregLocock]

Is the turbo from GM or is it an add-on? If the latter then the bsfc of the NA engine won't help.

Cheers

Greg Locock

SIGlease see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[msantiago]

The Turbo is a kit for that engine. I want to compare the engine to other engines NA with turbo kit. The BSFC data on the NA engine would allow me to compare the NA engines as a reference.

 

[GregLocock]

No it won't. Unless you are very clever. And then it won't, but with smaller errors.

Cheers

Greg Locock

SIGlease see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[msantiago]

Greg, How will the turbo kit influence the BSFC on the engine? By looking to fuel consumption on Gen Sets with the same engine on Turbo and NA versions, comsuption seems to be very similar.

 

[patprimmer]

At a wild guess, I would say it will:-

Require a lower CR.
have a different pressure over the piston on the induction stroke.
Have a different pressure over the piston on the exhaust stroke.
Have a different pressure in the chamber at point of ignition.
Have a different pressure build up rate during combustion.
Have a different level of exhaust scavenging during overlap to the point that intake charge is also scavenged out the exhaust or passive EGR is occuring.

Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers &

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[patprimmer]

Oh

And the impact of retarding the ignition to avoid detonation.

Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers &

http://eng-tips.com/market.cfm

for site rules

 

[BrianPetersen]

Although it's supposedly *possible* to tune a turbo gasoline engine to give the power of a bigger engine while retaining the economy of the smaller engine, that hasn't been the "actual field experience" of a couple of turbo gas engine automobiles in my family: they had the same real world lousy economy of a bigger engine without the turbo but about the same power rating. And those were modern, supposedly somewhat high-tech, electronically controlled and intercooled engines.

 

[Bribyk]

I believe the engine you are referring to is called the "8.1LT" and is commonly used for portable power generation. A search of "8.1LT generator" should turn up a few generator packager's datasheets. GM doesn't show a turbo as an option on their Industrial Engines but it's common to add an aftermarket turbo when running propane or nat gas.

Brian Bobyk - Hoerbiger Canada

 

[msantiago]

Hello Brian,

You are right, this is the engine I am looking for, by the datasheet of generators the efficiency of the engine is similar on the NA engine compared to the Turbo. I am looking for some field experiences with that engine and engine integrators that can supply the engine with the turbo kit, so far I only found the supply for the NA engine.

 

[Bribyk]

A turbo doesn't appreciably reduce peak (full load and speed) fuel consumption on these types of engines (rich burn, nat gas or propane). You do however get more power out of the same engine footprint/weight and better fuel consumption at lower loads.

Also, keep in mind you probably won't achieve the manufacturer's fuel consumption rating in field service.

This engine and application was discussed on, I believe, this forum not too long ago. See if you can find that thread for some additional info.

Brian Bobyk - Hoerbiger Canada

 

[Bribyk]

This is the thread but I see you've probably already read it

thread71-252760

Brian